Field of the Invention
The present invention relates to a liquid discharge head that discharges a liquid droplet and a method for manufacturing the liquid discharge head.
Description of the Related Art
As an example of a configuration of a liquid discharge head, a configuration disclosed in Japanese Patent Laid-Open No. 2003-311964 (hereinafter referred to as Patent Document 1) in which at least two or more discharge portions, each of which is capable of discharging a liquid droplet having a size different from that of the liquid droplet discharged by the other discharge portion, are disposed in one chip is known. With this configuration, a liquid discharge head that is capable of discharging liquid droplets having a plurality of sizes from a single chip by changing the substantial volume of a liquid, which is applied with pressure generated when part of the liquid bubbles, may be obtained. In particular, in the invention disclosed in Patent Document 1, the diameters of discharge ports that are formed in a chip for discharging a liquid, the areas of heating resistors that cause the liquid to bubble, and the planar sizes of pressure chambers in which the heating resistors are formed are varied.
Japanese Patent Laid-Open No. 2007-216415 (hereinafter referred to as Patent Document 2) discloses a liquid discharge head capable of discharging liquid droplets having a plurality of sizes from a single chip by varying the sizes of pressure chambers in a height direction by varying the thicknesses of portions of a discharge-port-forming member in which discharge ports are formed, that is, the heights of the portions of the discharge-port-forming member from a surface in which heating resistors are installed to the discharge ports.
In the case of the liquid discharge head disclosed in Patent Document 1, in order to vary the sizes of liquid droplets to be discharged, it is primarily necessary to vary the planar sizes of the pressure chambers so as to vary the volumes of the pressure chambers. Thus, in order to discharge a large liquid droplet, a pressure chamber having an area large enough to discharge the large liquid droplet needs to be formed, and the liquid discharge head has a limitation with regard to densely arranging a plurality of discharge ports.
On the other hand, the liquid discharge head disclosed in Patent Document 2 is advantageous for the dense arrangement of discharge ports since the sizes of the pressure chambers are varied in the height direction. However, in the invention disclosed in Patent Document 2, a surface of the discharge-port-forming member in which the discharge ports are formed (hereinafter referred to as a discharge-port surface) has differences in level. In the field of inkjet recording heads, in general, in order to remove a liquid adhering to a discharge-port surface and to prevent a discharge abnormality from occurring or recover from the discharge abnormality, wiping of the discharge-port surface is performed. Thus, in the case where the discharge-port surface has a difference in level, there have been problems in that it is difficult to properly wipe the discharge ports positioned at a lower level, and that it is difficult to ensure reliability against long-term use.
Accordingly, in view of the above-mentioned problems in the related art, the present invention is directed to a configuration of a liquid discharge head that is capable of having a dense arrangement of discharge ports and efficiently performing wiping of a discharge-port surface.